It is well known that many animal cells need to be anchored to a surface in order to grow. Cells requiring surface attachment are for example keratinocytes, fibroblasts, myocardiocytes, ovary cells, hepatocytes, Langerhans islets.
In many medical applications a matrix is provided to which cells can adhere thus facilitating cell growth. For example in treatment of burn wounds or other open wounds sheet materials on which keratinocytes and/or fibroblasts are grown are used as skin replacements as described in for example WO 00/29553.
Cell supports are used in a variety of applications in which cell attachment is important for proliferation of the cells. Gelatin is a well known substrate for cell attachment. It is used as a coating on carrier materials such as polystyrene or glass particles for cell culturing. Application of gelatin as a scaffold in tissue engineering or as a coating of implant materials is also known. In most cases the gelatin is crosslinked. However, gelatin has several drawbacks. Being from a natural source the composition is in principle undefined, and contaminations such as proteins, viruses and prions may be present requiring further measures to guarantee biocompatibility.
WO 2005/079879 describes a process for producing cell carrier or medical material consisting of crosslinked collagen fibers. Crosslinked gelatin layers are also used to coat implants. WO 00/6701 describes the use of gelatin scaffolds for cell adhesion in repairing myocardial scar tissue or for coating pacemakers.
For in vitro cultivation of cells such as for example yeast cells or animal cells, carriers are used that provide a surface for cell-attachment. The cell-binding properties of such surfaces can be enhanced by coating with gelatin, or the carrier may consist of crosslinked gelatin particles.
EP 0 222 718 describes macroporous particles that are suitable as microcarriers for cultivation of anchor-dependent cells, but is silent with respect to properties other than macroporosity. Preparation of gelatin microcarriers is described in for example WO 90/13625, SU 1724687, WO 02/48247 and WO 03/104313.